Tire systems are evolving from passive mechanical elements into active sensing and energy harvesting platforms. The concept of “rechargeable tires” integrates wearable tire sensors with embedded energy-harvesting mechanisms to power sensor electronics autonomously. This evolution aims to reduce reliance on battery replacement, extend sensor lifetime, and feed data for advanced safety, performance, and predictive maintenance systems in vehicles. This article examines sensor integration in tires, energy harvesting technologies applicable to tires, challenges in realizing self-charging tire systems, and selected prototypes and research breakthroughs.
Kings Research estimates that the global rechargeable tires market is projected to reach USD 1,637.3 million by 2031, growing at a CAGR of 33.02% from 2024 to 2031.
How tire sensors have evolved from TPMS to fully smart, data-driven tires
Tire pressure monitoring systems (TPMS) represent the earliest widespread tire sensors. Most modern vehicles include direct or indirect TPMS to detect underinflation, thereby enhancing safety and fuel efficiency. Direct TPMS sensors are mounted in the wheel and report pressure and sometimes temperature via RF transmitters.
Advancements in materials, electronics, and wireless communications enable deeper sensing functions: strain, tire wear, road friction, vibration, temperature, and dynamic load. Integration of these sensors within the tire structure or inner lining demands extremely low-power designs and novel energy sources. Sensor arrays in “smart tires” can monitor multiple parameters to inform vehicle control systems, predictive maintenance, and real-time safety interventions. Research literature demonstrates sensor arrays in tires for monitoring road surface, deformation, and tread strain.
A significant advancement appeared in Nature Communications: researchers developed a 3D printed graphene-based strain sensor, paired with a flexible piezoelectric energy harvester, enabling self-powered wireless sensing in tires. That system integrated both sensing and energy harvesting in a unified structure.
Self-powered pressure/temperature detectors have also been proposed, showing potential for tire sensors that draw power from rotational or vibrational motion. A recent study presented self-powered temperature and pressure detection in tires, analyzing energy recovery potential from thermal gradients and mechanical deformation.
The energy harvesting technologies powering self-charging tire sensors
Harvesting energy from tires must contend with constraints: limited space, varying speeds, variable deformation, dynamic loads, and durability demands. Several energy harvesting modalities show promise in this context.
Piezoelectric Harvesting:
Deformations and vibrations of the tire under load can be converted into electrical energy using piezoelectric materials. A study on energy harvesting in pneumatic tires using piezoelectric materials quantified harvested energy under typical driving deformations and assessed life cycle performance. (Source: pubs.aip.org)
A newly published “self-powered pressure monitoring system” relies on a piezoelectric harvester to power sensors under rotational vibration. That system operates without external power and switches its operating states in response to vibration patterns.
Piezoelectric harvesters face challenges such as matching mechanical resonance, fatigue under repeated bending, limited energy output at low speeds or steady motion, and integration with deforming tire structures.
Electromagnetic and Inductive or Wireless Power Transfer (WPT):
Some designs propose electromagnetic coupling or induction to transfer power across the rotating boundary between the chassis and wheel hub. A powering strategy described in MDPI Electronics proposes mounting transmitter coils on the inner fender liner and receiver coils embedded in the tire inner wall. That system achieved a stable DC voltage and current (≈ 4.3 V at ~21 mA) across a range of rotational speeds up to 800 rpm in simulation.
Wireless power transfer systems offer the ability to energize sensors even at low speeds or when stationary, provided alignment of coil systems is maintained. The challenge lies in achieving sufficient coupling across gaps, misalignment resilience, coil geometry constraints, and minimizing electromagnetic interference.
Hybrid Techniques and Advanced Materials:
Combinations of piezoelectric, electromagnetic, triboelectric, and thermoelectric harvesting may enhance reliability and broaden operational conditions. Recent reviews describe how coupling multiple energy harvesting modalities supports continuous power in variable dynamic environments. (Source: pmc.ncbi.nlm.nih.gov)
Innovations in materials, such as embedding CNTs in elastomers or composite piezoelectric films, support flexible energy harvesters tailored for tire curvature and strain cycles. A recent investigation into energy harvesting using a multi-walled carbon nanotube (MWCNT) concentration explores sustainable and renewable energy options in tire structures.
Integrating Energy Harvesters and Sensors into Tires
Sensor and Harvester Co-Design:
Sensor electronics, energy storage (e.g., microcapacitor or rechargeable microbattery), and harvester elements must be co-designed respecting constraints of flexibility, durability, size, weight, and dynamic stress. The graphene-based sensor example demonstrates direct integration of the energy harvester and sensing patch, reducing interconnect losses.
Complex deformation, rotational speed, thermal cycling, moisture ingress, and mechanical fatigue require rugged packaging, encapsulation, and strain relief design. The electronics must operate across wide temperature, humidity, and vibration ranges found in tire environments.
Design must ensure that the energy harvested suffices to power sensing, processing, wireless transmission, and perhaps local storage overheads. Duty cycling, low power modes, energy budgeting, and adaptive operation are key strategies.
Data Communication and Processing:
Wireless communication from rotating components (tires) to the vehicle body typically uses RF links or inductive coupling. Energy budgets constrain data rates and transmission intervals. Local preprocessing or aggregation reduces data transmission load. Edge computing on sensor modules may filter relevant events (e.g., wear threshold, anomaly) rather than streaming continuous data.
Security, latency, and reliability are critical because sensor data may feed safety systems, braking control, traction control, or predictive maintenance modules.
Lifecycle, Maintenance, and Reusability:
Rechargeable tires must ensure longevity over multiple years and tens of thousands of kilometers. Energy harvesters should not degrade prematurely. Modular or replaceable sensor modules may help maintainability. Because batteries degrade, combining energy harvesting with small-capacity energy storage enables a buffer during low-harvesting periods.
Reusability is relevant: sensor modules may need replacement at the tire lifecycle end. Designing detachability or modularity in the sensor-harvester system contributes to sustainability and serviceability.
Prototype and research demonstrations of self-charging tire sensor systems
- TDK’s InWheelSense Module: TDK introduced InWheelSense, a piezoelectric energy harvesting and sensing module designed for wheel environments. It harvests mechanical forces and powers embedded sensors, eliminating the need for dedicated batteries. The module is placed near the tire bead, a location of maximal mechanical stress, enabling perpetual power to sensor electronics and data collection. (Source: www.sae.org) The module captures both power and sensor signals, enabling dual functionality. That integrated approach exemplifies practical steps toward wearable, self-powered tire sensors.
- Self-Charging Pressure Monitoring Systems: The recent study on a self-powered pressure monitoring system elaborates a rotating vibration energy harvesting scheme that powers pressure sensors autonomously. That system avoids battery replacement and sustains sensing under various speed regimes.
- Simulation Studies of Electromagnetic Charging: The MDPI Electronics powering strategy simulation shows the feasibility of wireless energy transfer to embedded sensors in rotating tire systems. Though not a commercial product, it offers a proof of concept for inductive coupling in realistic vehicular motion scenarios.
Challenges and Constraints
- Power Density and Energy Balance: Harvested energy typically lies in the microwatt to milliwatt range, which must power all sensor, processing, transmission, and storage needs. Efficiency losses, misalignment, losses in conversion, and periods of low harvesting (low speed, idle) challenge consistent operation. Harvester fatigue and mechanical degradation under repeated stress cycles present durability concerns. Piezoelectric elements or electromagnetic coils must maintain performance under continuous deformation, temperature extremes, and mechanical shocks.
- Efficiency and Coupling in Wireless Transfer: Wireless power systems must maintain coupling despite misalignment, air gaps, and relative movement. Efficiency drops with distance, angular misalignment, and coil geometry discrepancies. Minimizing electromagnetic interference with vehicle systems is also critical.
- Integration, Packaging, and Reliability: Embedding sensors and harvesters inside tires demands robust packaging, protection against moisture, mechanical clearance, and ensuring that these additions do not compromise tire integrity, handling, comfort, or balance. Manufacturing methods must accommodate adding electronics into tire layers during vulcanization or after. Testing and validation across full vehicle lifetimes, under real road conditions, temperature cycles, speed variation, and safety certification are nontrivial. Standardization and regulatory acceptance of sensor data for safety-critical systems an obstacle.
- Cost, Weight, and Tradeoffs: Adding sensors and harvesters increases cost, complexity, and slight mass. That additional mass must not offset gains in sensor benefits. OEMs will demand cost-effective, high-reliability modules. Scaling from prototype to mass production is a major hurdle.
Future opportunities and innovations for self-powered, smart tire systems
The convergence of autonomous vehicles, predictive maintenance, connected vehicles, and intelligent tire systems drives demand for embedded sensing. Self-charging tire sensors complement that trend. Some opportunities stand out:
Tire manufacturers and sensor firms can collaborate to embed self-powered sensing modules in next-generation tires. Data from embedded sensors can feed real-time friction estimation, wear prediction, road-surface mapping, and emergency response.
Energy harvesting designs optimized across multiple modalities (piezoelectric + electromagnetic + thermoelectric) can ensure more stable power across variable driving conditions. Hybrid harvesters yield redundancy and stability.
Advances in low-power electronics, energy-efficient wireless protocols, edge computing, and miniaturization reduce the energy budget burden and increase the viability of self-powered tire systems.
Standards and regulatory pathways for sensing in tires must emerge, especially if sensor outputs feed safety systems. Collaboration with automotive OEMs, standard bodies, and regulatory agencies is essential.
Commercial pilots could begin in fleets, where maintenance, telemetry, and data infrastructure are already in place. Fleet deployment helps validate reliability, serviceability, and data integration before consumer-scale adoption.
Conclusion
Wearable tire sensors and self-charging, rechargeable tire systems represent a transformative step in vehicle sensing and intelligence. Advances in piezoelectric energy harvesting, wireless power transfer, and low-power sensor integration are drawing the concept closer to feasibility. Demonstrations such as TDK’s InWheelSense module and self-powered pressure monitoring systems showcase that energy harvesting from tire deformation is possible.
Challenges remain in power density, packaging, durability, system integration, cost, and regulatory acceptance. The path forward lies in hybrid harvesting strategies, optimized electronics, rugged packaging, and collaboration with OEMs and standards bodies. Rechargeable tires could provide continuous sensing, reduce maintenance, and enable new safety and performance features in automobiles.
